Wheel rotating device for airplanes



March 20, 19 L. D. YOUNG ETAL WHEEL ROTATING DEVICE FOR AIRPLANES 2 Sheets-Sheet 1 Filed April 12, 1960 INVENTORS 2 .1 E I I w B @Www' March 20, 1962 D. YOUNG ETAL 3,026,069

WHEEL ROTATING DEVICE FOR AIRPLANES Filed April 12, 1960 2 Sheets-Sheet 2 mom SURGE COMPRESSOR TANK United States Patent Ofiflce 3,026,069 Patented Mar. 20, 1962 3,026,069 WHEEL ROTATING DEVICE FOR AIRPLANES Leparis D. Young, 1518 Zelda Way, and Joe Umeda, 807 Vallejo Way, both of Sacramento, Calif. Filed Apr. 12, 1960, Ser. No. 21,820 2 Claims. (Cl. 244-103) This invention relates in general to an improvement in airplanes.

In particular, the invention is directed to-and it is a major object to provide-a novel device for causing rotation of airplane wheels prior to landing; the primary purpose being to reduce the wear and tear on the tires caused by the frictional contact thereof with the runway, such as occurs when the wheels are not turning at the time of landing and are first placed in motion by such contact. An added advantage is that smoother landing can be accomplished, and without tendency of lateral skidding-especially when the runway is wet or icy-if one wheel touches the runway before the opposite wheel does so.

Another object of this invention is to provide a wheel rotating device, as above, which includes a novel assembly of wheel mounted, fluid pressure nozzles arranged to produce-by reaction from such nozzles-the desired pre-landing rotation of the wheels, and in the proper direction of turning.

Another object of the invention is to provide a device, for the purpose described, which includes a novel valve controlled, fluid pressure supply conduit system operative not only to deliver fluid pressure to the nozzles but to an extent to effect pre-landing rotation of the airplane wheels at a peripheral speed approximating the estimated landing speed of the airplane.

It is also an object of the invention to provide a practical, reliable, and durable wheel rotating device for airplanes, and one which will be exceedingly eflective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings:

FIG. 1 is a fragmentary diagrammatic front elevation of a tricycle landing wheel type airplane; the present device being shown as mounted on the primary or transversely spaced landing wheels.

FIG. 2 is an enlarged side elevation of one of the landing wheels as provided with such device.

FIG. 3 is a fragmentary transverse elevation of such wheel, partly broken away and mainly in section; the view being taken essentially on line 3--3 of FIG. 2.

FIG. 4 is a diagram of the valve controlled, fluid pressure supply conduit system.

FIG. 5 is a fragmentary elevation showing one of the fluid pressure nozzles; the view being mainly in section.

Referring now more particularly to the drawings, and to the characters of reference marked thereon, the invention is here shown, for the purpose of illustration, in connection with an airplane, shown in part at 1, of tricycle landing type; such airplane including wheel struts 2 which carry primary or transversely spaced landing wheels, indicated generally at 3. The remaining or central forward wheel is indicated at 4.

In the present illustration the wheels 3 are each fitted with the wheel rotating device, and which is indicated generally at 5. Though not so shown, the wheel 4 could likewise be provided with one of the devices 5 if desired.

Each wheel 3, and the device 5 thereon, is identical, except for being left and right hand, and therefore a description of one wheel, and the device thereon, will suflice for both.

Each wheel 3 carries a tire 6 retained by an inner wheel flange 7 and an outer wheel flange 8.

A spindle 9, which is tubular for the purpose hereinafter described, is fixed in connection with and projects horizontally outwardly from the lower end of the related strut 2. The wheel 3 is turnably mounted on the spindle 9 by means of a bearing assembly 10 which includes the usual seals, as shown, and an outer retention nut 11. The numeral 12 indicates part of the brake assembly, while the numeral 13 indicates a portion of the brake actuating unit.

Each of the wheel rotating devices 5 comprises a short radial pipe 14 disposed outwardly and in centralized relation to the outer end of the spindle 9 of the corresponding wheel 3; such pipe 14 being coupled, at its ends, by unions 15 to right angle elbows 16 which extend in opposition to each other in the plane of rotation of the wheel.

Each such elbow 16 is formed, at its outer or free end, with a fluid pressure nozzle, indicated generally at 17. The nozzles, as formed on the outer ends of the elbows 16, thus discharge in opposite directions and substantially tangent to the wheel 3. The radial pipe 14 and the right angle elbow 16 are dimensioned so that the nozzles 17 lie laterally out from the outer wheel flange 8.

Also, the nozzles 17 each face or discharge in a direction contra to the direction in which the wheel '3 is to be pre-rotated for landing, and wherein such wheel turns rearwardly at the bottom.

Intermediate its ends, and on the inner side, the pipe 14 is formed with an opening 18 axially alined with, but spaced outwardly from the adjacent end of the tubular spindle 9.

A rotary coupling, indicated generally at 19, and which may be a Barco flexible ball joint, is connected in pressure-tight relation between the pipe 14 and the spindle 9, whereby to establish communication between the opening 18 and the interior of said spindle 9, yet without restricting rotation of the wheel 3, while permitting the pipe 14 to rotate therewith. The rotary coupling 19 includes, together with the ball joint assembly as shown, a neck 20 secured to the pipe 14, and a nipple 21 threaded into the adjacent end of the tubular spindle 9.

The rigid assembly, comprised of the pipe 14 and the opposed right angle elbows 16, is fixedly mounted on the wheel 3, and for rotation therewith, by means of standofl brackets 22 which are clamped about the elbows 16, as at 23.

From the elbows 16 the brackets 22 extend inwardly and are formed with cars 24 attached to the wheel 3 by the wheel flange mounting bolts 25.

A fluid pressure supply conduit 26, of solid tubing, or flexible metallic woven type, leads to adjacent the inner end of the tubular spindle 9; such conduit 26 being connected in communication with such spindle by a union 27 and a nipple 28 which is threaded into said spindle.

The fluid pressure conduit 26 for each wheel 3 leads along the related strut 2, as shown in FIG. 1, and enters the fuselage of the airplane 1.

Within such fuselage the conduits 26 communicate with a common fluid pressure supply conduit 29 which leads from an air compressor or other fluid pressure source in the airplane.

From such compressor or the like the fluid pressure delivers to a surge tank 30 in conduit 29, which conduit also includesbetween such surge tank and the conduits 26a main or ofi-on valve 31; such valve 31 being disposed for control or manipulation by the pilot of the airplane. The valve 31 is normally in an off position.

A flow control valve 32 is interposed in the conduit 3 29 between the surge tank 30 and the main valve 31; such flow control valve 32 being adjustable .to regulate the amount of fluid pressure delivering through the described conduit system to the devices when the main valve 31 is opened.

The valve 32 thus controls the speed at which the wheels 3 will be rotated by the devices 5. Such valve 32, if of manual type, is scaled to indicate to the pilot the settings which will produce certain rotative speeds of the wheels 3; such valve in the present instance being shown as set for a landing speedof 125 miles per hour.

It is also contemplated that the flow control valve 32 may be automatically regulatedthrough a servo mechanism-from the air speed indicator of the airplane; the connection being indicated diagrammatically and in part at 33.

In a further adaptation, and wherein the airplane always has substantially the same landing speed, the valve 32 could be substituted by a fixed orifice.

To place the wheels 3 in pre-rotation and preparatory to landing of the airplane 1, the pilot first sets the flow control valve 32 and then opens the main valve 31,

. whereupon fluid pressure delivers through the conduits 29 and 26, through the tubular spindles 9, and into the pipes 14 and the related opposed right angle elbows 16. The fluid'pressure then forcefully discharges through the opposed nozzles 17 and out therefrom; the force of reaction producing rotation of the wheels 3 in the proper direction, and at a speed approximating the landing speed of the airplane. As a result, when the airplane initially touches down on the runway upon landing, the tires 6 contact the runway with a minimum of frictional sliding, so that wear and tear on the tires is greatly reduced, and the landing is accomplished much smoother than otherwise.

In order to produce the maximum reaction from the nozzles 17 as the fluid pressure discharges therefrom as a jet, each such nozzle comprises-at its inner end portion-a forwardly tapering throat 34, and at its outer end an enlarged bell 35; the point of merger between the throat 34 and bell 35 providing a venturi restriction 36.

As the fluid pressure passes through the restriction 36 the jet of such pressure expands within the bell 35 to enhance the reaction which produces the desired Wheel rotation.

While the present invention is illustrated as used in connection with an airplane having fixed struts and landing wheels, such invention is also readily adaptable to an airplane wherein the struts and wheels are retractible. In this latter instance the conduits 26 would be of flexible type, or otherwise suitably arranged to permit of the retraction of the wheels.

From the foregoing description it will be readily seen that there has been produced such a device as will substantially fulfill the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations therefrom may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described the invention, the following is claimed as new and useful, and upon which Letters Patent are desired:

1. In an airplane having a landing wheel and a tubular non-rotative spindle on which the wheel is mounted, a rigid conduit member projecting radially of and laterally out from the spindle and wheel, means securing the member on the wheel for rotation therewith, a nozzle on the outer end of the member facing in a direction opposite to the intended direction of rotation of the wheel, means to feed a gas under pressure into the laterally inner end of the spindle, and a rotary tubular coupling connecting the conduit member and the outer end of the spindle and providing unrestricted and uninterrupted communication therewith.

2. A structure, as in claim 1, in which the nozzle comprises a forwardly tapering throat portion, and an enlarged discharge bell projecting forwardly from said taper portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,330,056 Howard Sept. 21, 1943 2,386,301 Duke et al. Oct. 9, 1945 2,414,849 Beazley J an. 28, 1947 2,452,633 Cautley Nov. 2, 1948 2,669,836 Abbott Feb. 23, 1954 FOREIGN PATENTS 90,784 Germany Feb. 15, 1897 

